Dual-effect heat dissipating fan

ABSTRACT

A dual-effect heat dissipating fan comprising an axial flow fan and an eccentric fan is disclosed. The top of the eccentric fan is a dome. The upper end of blades of the eccentric flow fan are aligned with the blade at the lower end in the same axial line so that the two are overlapped and thus. The airflow guided therein will concentrate in this area and then is blown out in an eccentric way; and therefore, the efficiency of heat dissipating is improved.

BACKGROUND OF THE INVENTION

[0001] The present invention relates to a dual-effect heat dissipating fan, especially in that fan, air is absorbed by an axial flow fan and is blown out by an eccentric fan so as to generate a maximum amount of wind.

[0002] In general, a fan has is a cylinder with a flat bottom, and blades are formed on the outer side of the cylinder. Due to the confinement of manufacturing a mold for a fan. In general, the blades of the fan can not be arranged on the same axial line so that two blades are spaced with a gap. Form the viewpoint of dynamics, the conventional fan can not increase the amount of output wind due to design of the heat dissipating fan. From the experience of design, after using, the designer also feels the following defects:

[0003] 1. Since the upper end of the conventional blades is flat, the absorbed wind due to the rotation of the fan at the upper end is finite due to no guide medium. Therefore, the wind force is small.

[0004] 2. Since the gap between blades is large, the wind can not be concentrated and be blown out. The wind is dispersed, and thus the amount of the output wind is not sufficient. As a result, heat dissipation is bad.

SUMMARY OF THE INVENTION

[0005] Accordingly, the primary object of the present invention is to provide a dual-effect heat dissipating fan, the upper end is an axial flow fan formed by round blocks, and is divided into a plurality of blades, and the lower end is a cylinder with a dome at the upper end. Then an eccentric fan is formed, which is symmetrical to the upper blades.

[0006] By the cambered surface at the lower cylinder, as the blade rotates, an absorption force will generate so as to absorb air to flow along the dome and then flows to the eccentric fan so that the air is blown out by the eccentric fan. Since in the present invention, the fan blade is divided into two parts, they can be molded separately. After the upper and lower blades are assembled. Two blades can be formed at the same axial line (the upper end of a blade is overlapped with the lower end of another blade in the same axial line, but they are arranged separately) so that the upper air will concentrate in this area. Then, it is blown out through the rotation of the blades so that a maximum wind is blown out, and therefore, the heat dissipating efficiency is improved.

[0007] The various objects and advantages of the present invention will be more readily understood from the following detailed description when read in conjunction with the appended drawing.

BRIEF DESCRIPTION OF THE DRAWINGS

[0008]FIG. 1 is an exploded perspective view of the present invention.

[0009]FIG. 2 is an assembled perspective view of the present invention.

[0010]FIG. 3 is an assembled cross sectional view of the present invention.

[0011]FIG. 4 shows the airflow distribution of the present invention.

[0012]FIG. 5 shows another airflow distribution of the present invention.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0013] Referring to FIGS. 1 and 2, the fan of the present invention is mainly formed by an axial flow fan 1 and an eccentric fan 2.

[0014] The axial flow fan 1 is located at an upper end and has a round block 10 structure. A plurality of blades 11 are distributed from the center to the outer circumference.

[0015] The eccentric fan 2 is located at a lower end and is structured as a cylinder. The top thereof is like a dome 22. The dome 22 is formed with a recess surface 220 for receiving the round block 10 at the upper end. Then a cover 221 covers thereon (see FIG. 3). Likewise, the outer periphery thereof are extended with a plurality of blades 20. The positions and number of the blades 20 is correspondent to the blades 11 at the upper ends. An axial hole 23 is located at the center of the cylinder, which serves to be passed through by the rotary shaft 3 so as to be connected and fixed to the round block 10 and the cylinder body. Therefore, the axial flow fan 1 and the eccentric fan 2 are assembled as the main body of a dual-effect heat dissipating fan of the present invention. Then, a coil 4 and a motor casing 5 are applied thereon. The fan is fixed to a heat radiator (not show) by a rotary shaft 3 so as to provide a preferred heat dissipating effect.

[0016] Further referring to FIGS. 4 and 5, when the fan rotates by the driving of a motor. The airflow in the upper end is guided into the eccentric fan 2 along the cambered surface of the dome 22. Since in the arrangement of the fan, the upper end of the blade 11 are aligned with the blade 20 at the lower end in the same axial line so that the two are overlapped so that the airflow guided therein will concentrate in this area and then is blown out in an eccentric way. The amount of wind will not expand and therefore, the efficiency of heat dissipating is improved.

[0017] The present invention is thus described, it will be obvious that the same may be varied in many ways. Such variations are not to be regarded as a departure from the spirit and scope of the present invention, and all such modifications as would be obvious to one skilled in the art are intended to be included within the scope of the following claims. 

What is claimed is:
 1. A dual-effect heat dissipating fan comprising an axial flow fan and an eccentric fan; wherein: an axial flow fan is a round block and a plurality of blades is distributed from a center portion to an outer circumference thereof; thus, the round block is firmly secured to the eccentric fan; a top of the eccentric fan is a dome; an outer periphery thereof are extended with a plurality of blades; blades is connected to the blades at upper ends; then, a coil and a motor casing are applied thereon; when the fan rotates by driving of the motor; the airflow in the axial flow fan is guided into the eccentric fan along an cambered surface of the dome; by the arrangement of the fan, upper ends of the blades are aligned with the blade at eccentric fan in the same axial line so that the two are overlapped and thus, the airflow guided therein will concentrate in this area and then is blown out in an eccentric way; therefore, the efficiency of heat dissipating is improved. 